This invention relates to sample collectors.
In one class of sample collector, a series of discrete volumes of liquid are collected within separate containers from a larger body of liquid for later analysis. They are collected by a pumping system that pumps samples from the liquid being monitored and deposits each of the samples into a different container.
In the prior art sample collectors of this class, the volume of each sample is controlled by depositing the sample in a separate measuring container and then emptying the container after the container is filled to a fixed volume or else controlling the amount of time or the number of strokes of the pump from the start of pumping until the liquid has been deposited into a sample collector or a combination of these two techniques.
The prior art systems have several disadvantages such as: (1) when a separate container is used, the opportunities for contamination are increased and the apparatus tends to be more complicated and expensive; and (2) when time or number of strokes are counted from the beginning of the sampling period, the volume varies under some circumstances with the viscosity of the fluid being pumped, with the escape of air and with similar variables.